Age - Late Jurrassic (150 to 200 MYA)
Origin - Arizona, New Mexico, Utah, and Colorado

Agatized fossilized dinosaur bones are petrified with silica or quartz crystals which gives them their colorful, glassy appearance. This process preserves the actual cell structure of the once living dinosaur. The wide variety of colors in agatized dinosaur bone is caused by minerals such as chlorite, chromium, iron-oxide and manganese that enter the cells during formation.